The present invention relates to improvements in containers in general, and more particularly to improvements in closures or caps for glass bottles, plastic bottles or analogous containers. Still more particularly, the invention relates to improvements in bottles or analogous containers which can be used for evacuation of pus or other liquid matter from animal bodies with the assistance from other-than-atmospheric pressure.
It is known to utilize vacuum-sealed liquid collection bottles in hospitals and similar institutions. The closure of the bottle is connected with a conduit which is placed adjacent to or into a wound to draw pus from the infected area and to thus promote the healing process. The liquid matter is caused to flow into one end of the conduit by evacuating air from the bottle whose closure is in communication with the other end of the conduit. As a rule, the conduit is discarded after a single use.
In certain presently known liquid collection bottles, the closure consists of a rubber disk which is overlapped by a nut made of synthetic plastic material and having internal threads in mesh with external threads on the neck portion of the bottle. The nut biases the disk against the end face of the neck portion so that the deformed disk establishes an airtight seal between the interior and exterior of the bottle. The means for indicating the presence and/or the extent of vacuum in the bottle forms an integral part of the disk. To this end, the latter is provided with two notches or recesses bounded at their outer ends by relatively thin elastic portions which constitute membranes and undergo deformation when the pressure at the outer side of the disk exceeds the pressure in the interior of the bottle. The membranes carry outwardly extending flags which are retracted into the disk when the pressure in the interior of the bottle is less than atmospheric pressure. Moreover, the flags move away from each other in response to deformation of the respective membranes so that, by observing the angle between the flags, a person can discern the presence as well as the extent of subatmospheric pressure in the interior of the bottle. A skilled nurse or another attendant in a hospital can determine whether or not the pressure in the bottle is sufficiently low to warrant the attachment of a conduit which is to evacuate liquid matter from wounds.
The recesses in the elastic disk are actually relatively deep blind bores. This presents problems when the apparatus must be cleaned and sterilized prior to renewed use, i.e., the cleaning of surfaces surrounding the deep blind bores is a time-consuming task and the person in charge is not absolutely sure whether or not such surfaces are sufficiently clean for renewed use of the disk. Furthermore, threading of the nut onto and detachment of the nut from the neck portion of the bottle is a time-consuming procedure.
U.S. Pat. No. 3,334,628 to Saemann et al. discloses a vacuum indicating connection for surgical wound-closing apparatus wherein the open end of the neck portion of a bottle is closed by an internally threaded cap and the open end is sealed by a rubber membrane which is overlapped by the cap and is pressed against the end face of the neck portion. The membrane is connected with a hose passing through a central opening of the end wall of the cap. When the pressure in the bottle is reduced below atmospheric pressure, the membrane bulges inwardly and pulls the adjacent end portion of the hose through the opening of the cap and into the neck portion of the bottle. Since the membrane is not observable from without, the patented device comprises a rather complex indicating system which can be observed by an attendant in order to determine the extent of subatmospheric pressure in the bottle. Such system includes a sleeve which extends outwardly from the end wall of the cap and has a window in line with different indicia on the hose. As the hose moves axially in response to deformation of the membrane, it places different indicia into register with the window which can be observed from without. The complexity of the indicating system contributes to initial cost and the sterilizing operation must be preceded by a time-consuming dismantling of the apparatus.